Studies On The Characteristic Of Growth And The Correlation With Physiological And Biochemical Indexes Of Young Walnut

Walnut is the major dry fruit species in china. Because of mainly using seedling-stocks in the production of walnut, at the same time, the source of stock's seed was nonstandard, thus it had a badly effect on the growth of walnut tree. Dwarfing and compact planting is a primary characteristic in fruit-tree cultivating now, By choosing suitable dwarfing rootstocks, early fruit, abundant products and excellent manufacture were obtained. The experiment mainly studied the characteristic of growth and the correlation with physiological and biochemical indexes of young walnut though paraffin-wax cut-section, colorimetric analysis and ELISA analysis. The main results were as follows:1.From one to three years, there were no obviously diversities in the growth of tree height and trunk girth between early bearing cultivars and late bearing cultivars. Early bearing walnut was dwarfish when they were mature, probably resulted from the early bearing.2.Wood/bark and shoot's resistor were all correlated with growth vigor. There was a significant positive correlation between wood/bark, shoot's resistor and the growth potential.3.Leaf thickness of cultivars were different, it also had no correlation with tree vigor. Palisade tissue's thickness was thicker than that of spongy tissue, There was a significant negative correlation between the ratio of palisade tissue/leaf thickness, palisade/spongy and the growth potential, and a positive correlation between the ratio of spongy tissue/leaf thickness, density of stomata and the tree vigor.4.Root's vessel density, wood/bark, wood area and the ratio of wood/whole area were found to be significantly in positive correlation with tree height, the bark percentage of the root's transverse area to be significantly in negative correlation with tree height. Root's transverse area and bark area all had no correlation with tree vigor.5.IAA and GA3 contents of root and bud of different cultivars were higher than that of Z and ABA contents, which indicated that the tree had strong nutrient-growth ability. GAs and ABA contents of different cultivars were distinct, they also had respectively significantpositive and negative correlation with tree height. IAA and Z contents had some effects on the tree vigor, but no obvious correlation with it.6.There was a significant negative correlation between POD activities of leaf or root and the growth potential of walnut, Root's IOD activities had a significant negative correlation with tree height and trunk vigor, which suggested that POD and IOD activities had remarkably influences upon the tree vigor.7. Wood/bark, palisade/spongy, vessel density, shoot's resistor, ABA and GAa contents, POD and IOD activities were all of the indexes which could predict tree vigor early. So it could offer reference for dwarfish identification and pre-selected of dwarf stock of walnut. Consequently, it was in favor of the development of dwarfing and compact planting of walnut in Hebei province.